Pump



Oct. 20, 1964 Filed Feb. 5, 1962 s. M. HOLLEY, JR

PUMP

2 Sheets-Sheet 2 INVENTOR. GA'ORGA' m. #0415), J,

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TORNEYS PU George M. Holley, .lrz, Grosse Pointe Farms, Mich, assignor to Holley Carburetor Company, Warren, Micin, a corporation of Michigan Filed Feb. 5, 1962, Ser. No. 171,197 Claims. (iii. 103-44) The present invention rel-ates to a fluid pump in which the medium to be delivered is impelled by a diaphragm which is hydraulically driven through a body of hydraulic oil or other suitable liquid by pressure and suction pulses produced by a reciprocating piston.

The diaphragm-piston pump of the present invention is characterized by the manner in which the clean or other fluid which is to be delivered to the work is completely and physically separated from the diaphragm driving mechanism and the fluid being pumped. This feature is particularly important when the fluid being pumped is corrosive or detrimental to the diaphragm driving mechanism.

The prior art illustrates low-constant volume diaphragm pumps wherein problems have resulted with the use of highly elastic diaphragms. One problem entailed the stretching or warping of the pumping diaphragm due to the pumping and return stroke range of the diaphragm. The second problem entailed controlling the intake and discharge of the hydraulic fluid being pumped. In the past, if the amount of hydraulic fluid was too large the stroke range of the diaphragm was displaced in the pressure stroke direction to such an extent that the diaphragm was excessively stressed and damaged. In addition, if the quantity of the hydraulic fluid was too small the diaphragm was also damaged due to excessive displacement of the diaphragm during the suction stroke.

It is an object of the present invention to provide a fluid pump in which the diaphragm is not subjected to excessive stretching and warping.

Another object of the present invention is to provide a pump comprising a housing, a diaphragm dividing the interior of the housing into (a pair of pumping chambers, a hydraulic reservoir in the housing, control passages with check valves connecting one of the chambers to the reservoir to provide a closed hydraulic system, a source of fluid connected to the other chamber, and a piston in said one chamber for directing the hydraulic fluid against the diaphragm to urge the diaphragm in a pressure stroke with respect to the fluid in the other chamber.

Still another object of the present invention is to provide a pump of the aforementioned type wherein a perforated domed lor concave plate is provided between the piston and the diaphragm in said one chamber to act as a seat or stop for the diaphragm on the return or suction stroke of the diaphragm.

A further object of the present invention is to provide a hydraulic actuated diaphragm pump of the aforementioned type which is characterized by the manner in which the piston when moving in its pumping stroke forces the diaphragm in its pumping stroke and displaces a greater amount of hydraulic fluid than the diaphragm does in the other chamber to insure the complete displacement of the fluid in the other chamber, whereby the excess hydraulic fluid is returned to the reservoir through one of the control passages and check valves.

A still further object of the present invention is to provide a hydraulic actuated diaphragm pump of the aforementioned type wherein the hydraulic pumping chamber is replenished on the suction stroke of the piston and diaphragm through the other of the control passages and check valvesto completely fill the expanding hydraulic pumping chamber with fluid.

3,153,381 Patented Oct. 20, 1964 hoe A further object of the present invention is to provide a pump of the aforementioned type which includes a more compact and integral valve assembly for the fluid being pumped so as to reduce the overall size of the pump.

It is thus another object of this invention to provide a simplified low cost structure of the aforementioned type having certain advantages contributing to efficiency, reliability and long life as well as ease of maintenance.

Other objects, advantages and novel details of construction of this invention will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawings, wherein:

FIGURE 1 is a top view in cross section, schematically shown and taken along line 1-1 of FIGURE 3 and looking in the direction of the arrows.

FIGURE 2 is a fragmentary enlargement in cross section of the diaphragm and valve assembly.

FIGURE 3 is an elevational view partly in cross section showing other details of the invention, taken along the line 3-3 of FIGURE 1 and looking in the direction of the arrows.

FIGURE 4 is a perspective view of the flapper valve which is a component of the air valve assembly.

Referring now to the drawings, FIGURES 1 and 3 illustrate a pump 10 for delivering air or other fluids. The pump 1% may be connected through its outlet 12 to almost any device such as the fluid motor 14 which has a piston 16 movable therein. The pump 10 includes a main body or housing 18 of circular cross-section which is provided with a main chamber or bore 20 closed at one end by the end cap 22 and is closed at the other end by suitable means including the closure plate 24. The end cap 22 is appropriately connected to the body 18 by means of a plurality of oircumferentially spaced axially extending bolts 26. The main chamber 20 is reduced in diameter as indicated at 28 to provide a bore or chamber for piston assembly 30. The chamber 23 defines part of the pumping chamber 32 which is mainly formed in the closure plate 24 as will subsequently be described.

The piston assembly 39 includes a cup-shaped piston 34 and extended balance arms 36 which are an integral part of the cup-shaped piston 34. The arms 36 are spaced apart and are provided with aligned openings or slots 38. Fixed to the main body or housing 18 of the pump 10 is an electric motor 40 which is provided with a shaft 42. The shaft 42 is rotatable in a bearing 44 carried by the housing 18. The shaft 42 has a reduced cylindrical shaft extension 46 which is rotatably received in bearing 48 provided in a wall of the housing 18 as illustrated in FIGURE 3. The eccentric cam Si) is secured to the shaft extension 46 by means of a key 52. The shaft extension 46 extends through the chamber 20, slots 38 and the opening provided in the eccentric cam 50 for the specific purpose of rotating the eccentric cam 59 and moving the piston assembly 30 in its pumping and suction strokes. A compression spring 56 is disposed between the wall 58 of the cup-shaped piston 34 and the end wall an of the closure plate 24 to force the cup-shaped piston 34 to the left as viewed in FIGURES 1 and 3 and to cause the eccentric cam 56 to continuously engage the wall 62 of the piston 34.

The closure plate 24 is provided with openings 66, 68 and 7d. The chamber 29 which is in communication with the eccentric cam 50 serves as a hydraulic reservoir. An inlet supply passage 72 is provided in housing 18 and connects the reservoir chamber 20 with the opening 68 provided in the closure plate 24. A hydraulic fluid return passage 74 is provided in the housing 18 and end cap 22 to connect the pumping chamber 32 to the reservoir chamber 2%. The hydraulicfluid return passage '74 is provided with a valve assembly 76 therein.

The valve assembly 76 includes a ball check '78, spring 80 and valve body 82. The valve body 82 has a hollow interior and is provided with an inlet opening or port 84 and an outlet opening or port S6. The spring 80 and the ball check 32 are located in the interior of the valve body 82 in a position where the spring 80 normally urges the ball check 82 against the ball seat provided in the inlet port 84 as illustrated in FIGURE 1.

The closure plate 24 is provided with another chamber 90 which has an inlet hydraulic valve assembly 92 that is similar to the valve assembly '76 with the exception that the ball check 94 has its seat in the inlet opening or port 26. The inlet passage '72 is therefore in communication with the pumping chamber 32 through means of the passage 68, chamber 90 and inlet port 96.

Mounted across the outer wall 100 of the closure 24 is a rigid plate 102 which includes a domed perforated portion 104 which is positioned in chamber 32. The domed perforated portion is convex towards the piston 34 and the perforations or openings therein are designated by the numeral 105. The outer periphery of the plate 102 abuts the outer wall 100 of the closure 24. A highly elastic diaphragm 106 is provided with a flexible intermediate portion 108 as illustrated in FIGURE 2. The outer periphery of the diaphragm 106 is in surface to surfacecontact with the outer periphery of the rigid plate 102. The housing 110 for the air valve to be subsequently described serves as an end cap for the pump and is clamped to the housing 18 by means of a plurality of circumferentially spaced screws 112 so as to locate the rigid plate 102, diaphragm 106, and closure plate 24 in a predetermined clamped position as illustrated in the drawing.

The inner wall 114 of the air valve housing 110 has a concave shape and serves as a seat for the. diaphragm 106 as will be subsequently described. The diaphragm 106 separates the pumping chamber 32 from the second pumping or auxiliary chamber 116 which is defined by the concave wall 114 of the air valve housing 110 and by the diaphragm 108. The chamber 116 is in the shape of a lens.

The air valve housing 110 is provided with a bore or opening 118 which terminates in the aforesaid outlet 12. Mounted in the bore 118 is a valve assembly 120. The valve assembly 120 includes a pair of stationary tubular members and a pair of flexible valve elements. The first tubular stationary member is designated by the numeral 122 and is provided with a flange 124 which engages the shoulder 126 provided in the interior of the air valve housing 110. The passage 128 in the first stationary member 122 has fixed therein a second stationary tubular member or hollow rivet 130. The tubular member 130 has a flange 131 which clamps the inner periphery of the flexible valve element 132 to the surface 133 of the first stationary member 122. The flexible valve 132 is generally made from rubber. The free outer periphery of the flexible valve element 132 is adapted to close the opening 134 provided between the chamber 116 and the chamber 138 defined by the passage 118 and the first stationary member 122. The outer periphery of the first flexible valve element 132 seats upon the wall 114 and closes the annular opening 134, according to a predetermined sequence as will be subsequently described.

A second flexible valve element 140 as best illustrated in FIGURES 2 and 4 is fixed to the rear surface 141 of the first stationary member 122 by means of the annular lip 142 of the cup retainer 144. The lip 142 holds the peripheral edge 146 of the valve element 140 in a fixed position. The flap valve 148 of the second flexible valve element 140 is separated from the major portion of the peripheral edge by an arcuate groove 147 and is adapted to move with respect to the interior of the second stationary tubular member 130. The flap valve 148 normally seats against surface 150 of the second tubular member 130 for closing the passage 152 provided therein.

The chamber 20, passage 72 and return passage '74 are all filled with hydraulic fluid as are adjacent passages and chambers connected therewith. The end cap 22 is provided with a plug 160 which permits the reservoir chamber 29 to be filled whenrequired. The chamber 138 of the air valve housing is connected by means of a passage 162 to a source of air or to a liquid under pressure as indicated by the numeral 164 in FIGURE 1. As previously mentioned, all the chambers and passages to the left or rear of the diaphragm 106 as viewed in FIGURE 1 are filled with hydraulic fluid and forms a closed hydraulic circuit. Chamber 116 and all of the other chambers and passages to the right of diaphragm 106 as viewed in FIGURE 1 contain air or the liquid to be pumped.

In operation, with the piston 34 at the bottom of its stroke as illustrated in FIGURE 1 and upon the rotation of the shaft 42 by the motor 40, piston 34 is moved to the right in its pumping stroke. While the piston 34 is moving to the right the pressure of the hydraulic fluid in the chamber 32 forces the fluid through the openings provided in the rigid plate 104. As a result the concave portion 108 of the diaphragm 106 is moved to the right as viewed in FIGURE 1. This causes the pressure of the air in chamber 116 to increase. The increased pressure urges the first flexible valve element 132 against the wall 114 of the air valve housing to prevent communication between the inlet chamber 138 and the pumping chamber 116. The increase in air pressure in chamber 116 is transmitted through passage 152against the flap valve 148. As a result the flap valve 148 is moved away from the end wall 150 of the second stationary member and allows the air or other fluid in chamber 116 to flow through passage 152, across the flap valve 148, and through openings 160 provided in the cup container 144 to the outlet 12.

On the return or suction stroke, the flapper valve 148 is urged against the end wall of the second stationary valve member 130, partly due to the back pressure in the outlet 12. The first valve element 132 is moved away from the Wall 114 thereby permitting air at atmospheric pressure or other fluid to enter chamber 116 from chamber 138 when diaphragm 106 returns to its original position due to the suction force of piston 34 and the onrushing air pressure acting in chamber 116 against the diaphragm 106. The diaphragm 106 may of course be spring loaded as is well known in the art to assist in its return on the suction stroke. Once the pumping and suction strokes have been completed the pumping cycle is repeated as required.

During the pumping stroke the volume displacement of the hydraulic fluid is greater than the displacement of air to insure complete displacement of the air in chamber 116. As a result, a small amount of hydraulic fluid is displaced from chamber 32 through the hydraulic return valve assembly 76 in the return passage 74 to the reservoir chamber 20. On the intake or pressure stroke a small amount of hydraulic fluid is sucked through the valve assembly 92 in the passage 72 into the pumping chamber 32 to completely fill the chamber 32. Spring 80 is of course strong enough to keep the ball check 82 upon its seat until all of the air is displaced from chamber 116.

The drawings and the foregoing specification constitute a description of the improved pump in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What I claim as my invention is:

1. A fluid pump comprising an elongated body having an inlet chamber, a pumping chamber, and an outlet chamber, all of said chambers being longitudinally aligned with said inlet chamber intermediate said other chambers, said pumping chamber being of lens shape configuration and consisting of a pair of converging side walls when said pumping chamber is at maximum capacity, one of said side walls adjacent said inlet chamber being integral with said body, the other of said side walls consisting of a movable diaphragm which is adapted to be moved towards said one side wall to displace the fluid in said pumping chamber, passage means in said body for supplying fluid to said inlet chamber, an annular zone of said one side wall immediately adjacent one end of said inlet chamber forming an annular valve seat, the other end of said inlet chamber adjacent said outlet chamber terminating in a shoulder, a valve member in said inlet chamber which is spaced from the walls of said inlet chamber, said valve member being provided on one end thereof with an outwardly extending flange engageable with said shoulder to close said other end of the inlet chamber, said valve member having a longitudinally extending centrally located passage therethrough connecting said pumping and outlet chambers, a relatively thin flexible inlet valve element having an intermediate portion fixedly carried by the other end of said valve member, the remaining portion of said inlet valve element spanning the space between said valve member and the walls of said inlet chamber and adapted to cooperate with said valve seat to control the flow of fluid between said inlet and pumping chambers, a relatively thin outlet valve element in said outlet chamber adjacent said flange, said outlet valve element including an integral flap valve which is surrounded by an arcuate passage having an angular extent of greater than 180, said flap valve being adapted to control flow across said passage between said pumping and outlet chambers, an annular retaining abutment in said outlet chamber including an annular peripheral flange engageable with the outer periphery of said outlet valve element to clamp said outlet valve element against said flange and said flange against said shoulder, said retaining abutment including passage means therein to permit flow through said outlet chamber, and actuating means for moving said diaphragm in a pressure stroke to create a pressure within said pumping chamber to urge said first valve element against said valve seat to seal said inlet chamber from said pumping chamber and transmit fluid from said pumping chamber through the passage in said valve member into said outlet chamber after urging said flap valve away from said one end of said valve member, said actuating means being effective to urge said diaphragm in a suction stroke to cause said flap valve to be urged in tight sealing engagement with the flange of said valve member due to the pressure of fluid in said outlet chamber and to cause said first valve element to be moved away from said valve seat to connect said inlet chamber with said pumping chamber.

2. A fluid pump comprising an elongated body having an inlet chamber, a pumping chamber, and an outlet chamber, all of said chambers beig longitudinally aligned with said inlet chamber intermediate said other chambers, said pumping chamber being of lens shape configuration and consisting of a pair of converging side walls when said pumping chamber is at maximum capacity, one of said side walls adjacent said inlet chamber being integral with said body, the other of said side walls consisting of a movable diaphragm which is adapted to be moved towards said one side wall to displace the fluid in said pumping chamber, passage means in said body for supplying fluid to said inlet chamber, an annular zone of said one side wall immediately adjacent one end of said inlet chamber forming an annular valve seat, the other end of said inlet chamber adjacent said outlet chamber terminating in a shoulder, and a removable valve assembly for controlling flow between said chambers comprising a valve member in said inlet chamber which is spaced from the walls of said inlet chamber, said valve member being provided on one end thereof with an outwardly extending flange engageable with said shoulder to close said other end of the inlet chamber, said valve member having a longitudinally extending centrally located passage therethrough connecting said pumping and outlet chambers, a relatively thin flexible inlet valve element having an intermediate portion fixedly carried by the other end of said valve member, the remaining portion of said inlet valve element spanning the space between said valve member and the walls of said inlet chamber and adapted to cooperate with said valve seat to control the flow of fluid between said inlet a and pumping chambers, a relatively thin outlet valve element in said outlet chamber adjacent said flange, said outlet valve element including an integral flap valve which is surrounded by an arcuate passage having an angular extent of greater than said flap valve being adapted to control flow across said passage between said pumping and outlet chambers, an annular retaining abutment in said outlet chamber including an annular peripheral flange engageable with the outer periphery of said outlet valve element to clamp said outlet valve element against said flange and said flange against said shoulder, said retaining abutment including passage means therein to permit flow through said outlet chamber, and actuating means for moving said diaphragm in a pressure stroke to create a pressure Within said pumping chamber to urge said first valve element against said valve seat to seal said inlet chamber from said pumping chamber and transmit fluid from said pumping chamber through the passage in said valve member into said outlet chamber after urging said flap valve away from said one end of said valve member, said actuating means being etfective to urge said diaphragm in a suction stroke to cause said flap valve to be urged in tight sealing engagement with the flange of said valve member due to the pressure of fluid in said outlet chamber and to cause said first valve element to be moved away from said valve seat to connect said inlet chamber with said pumping chamber, said valve assembly being removable from said body by initially removing said retaining abutment thereby permitting said outlet valve element and then said valve member and inlet valve element to be withdrawn from said body through said outlet chamber.

3. A fluid pump comprising a body having an inlet chamber, a pumping chamber, and an outlet chamber, all of said chambers being longitudinally aligned with said inlet chamber intermediate said other chambers, said pumping chamber including a pair of side walls, one of said side walls adjacent said inlet chamber being integral with said body, the other of said side walls consisting of a movable element which is adapted to be moved towards said one side wall to displace the fluid in said pumping chamber, passage means in said body for supplying fluid to said inlet chamber, an annular zone of said one side wall immediately adjacent one end of said inlet chamber forming an annular valve seat, the other end of said inlet chamber adjacent said outlet chamber terminating in a shoulder, a valve assembly for controlling flow between said chambers comprising a valve member in said inlet chamber which is spaced from the walls of said inlet chamber, said valve member being provided on one end thereof with an outwardly extending flange engageable with said shoulder to close said other end of the inlet chamber, said valve member having a longitudinally extending passage therethrough connecting said pumping and outlet chambers, a relatively thin flexible inlet valve element having an intermediate portion fixedly carried by the other end of said valve member, the remaining portion of said inlet valve element spanning the space between said valve member and the walls of said inlet chamber and adapted to cooperate with said valve seat to control the flow of fiuid between said inlet and pumping chambers, a relatively thin outlet valve element in said outlet chamber adjacent said flange, said outlet valve element including an integral flap valve which is surrounded by an arcuate passage, said flap valve being adapted to control flow across said passage between said pumping and outlet chambers, an annular retaining abutment in said outlet chamber including an annular peripheral flange engageable with the outer periphery of said outlet valve element to clamp said outlet valve element against said flange and said flange against said shoulder, said retaining abutment including passage means therein to permit fiow through said outlet chamber, and actuating means for moving said element in a pressure stroke to create a pressure within said pumping chamber to urge said first valve element against said valve seat to seal said inlet chamber from said pumping chamber and transmit fluid from said pumping chamber through the passage in said valve member into said outlet chamber after urging said flap valve away from said one end of said valve member, said actuating means being effective to urge said element in a suction stroke to cause said flap valve to be urged in tight sealing engagement with the flange of said valve member due to the pressure of fluid in said outlet chamber and to cause said first valve element to be moved away from said valve seat to connect said inlet chamber with said pumping chamber.

4. The fluid pump defined in claim 3 wherein said valve assembly is constructed and arranged for removal from said body by initially removing said retaining abutment thereby permitting said outlet valve element and then said valve member and inlet valve element to be withdrawn from said body through said outlet chamber.

5. A valve comprising a body having an inlet chamber, an auxiliary chamber, and an outlet chamber, all of said chambers being longitudinally aligned with said inlet chamber intermediate said other chambers, said inlet chamber terminating on one end thereof in an annular valve seat adjacent said auxiliary chamber, the other end of said inlet chamber adjacent said outlet chamber terminating in' a shoulder, a valve member in said inlet chamher which is spaced from the walls of said inlet chamber, said valve member being provided on one end thereof with an outwardly extending flange engageable with said shoulder to close saidother end of the inlet chamber, said valve chamber having a longitudinally extending cen- 8. trally located passage therethrough connecting said auxiliary and outlet chambers, a relatively thin flexible inlet valve element having an intermediate portion fixedly carried by the other end of said valve member, the remaining portion of said inlet valve element spanning the space between said valve member and the walls of said inlet chamber and adapted to cooperate with said valve seat to control the flow of fluid between said inlet and outlet chambers, a relatively thin outlet valve element in said outlet chamber adjacent said flange, said outlet valve element including an integral flap valve which is surrounded by an arcuate passage having an angular extent of greater than said flap valve being adapted to control flow across said passage between said auxiliary and outlet chambers, and an annular retaining abutment in said outlet chamber including an annular peripheral flange engageable with the outer periphery of said outlet valve element to clamp said outlet valve element against said flange and said flange against said shoulder, said retaining abutment including passage means therein to permit flow through said outlet chamber.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A FLUID PUMP COMPRISING AN ELONGATED BODY HAVING AN INLET CHAMBER, A PUMPING CHAMBER, AND AN OUTLET CHAMBER, ALL OF SAID CHAMBERS BEING LONGITUDINALLY ALIGNED WITH SAID INLET CHAMBER INTERMEDIATE SAID OTHER CHAMBERS, SAID PUMPING CHAMBER BEING OF LENS SHAPE CONFIGURATION AND CONSISTING OF A PAIR OF CONVERGING SIDE WALLS WHEN SAID PUMPING CHAMBER IS AT MAXIMUM CAPACITY, ONE OF SAID SIDE WALLS ADJACENT SAID INLET CHAMBER BEING INTEGRAL WITH SAID BODY, THE OTHER OF SAID SIDE WALLS CONSISTING OF A MOVABLE DIAPHRAGM WHICH IS ADAPTED TO BE MOVED TOWARDS SAID ONE SIDE WALL TO DISPLACE THE FLUID IN SAID PUMPING CHAMBER, PASSAGE MEANS IN SAID BODY FOR SUPPLYING FLUID TO SAID INLET CHAMBER, AN ANNULAR ZONE OF SAID ONE SIDE WALL IMMEDIATELY ADJACENT ONE END OF SAID INLET CHAMBER FORMING AN ANNULAR VALVE SEAT, THE OTHER END OF SAID INLET CHAMBER ADJACENT SAID OUTLET CHAMBER TERMINATING IN A SHOULDER, A VALVE MEMBER IN SAID INLET CHAMBER WHICH IS SPACED FROM THE WALLS OF SAID INLET CHAMBER, SAID VALVE MEMBER BEING PROVIDED ON ONE END THEREOF WITH AN OUTWARDLY EXTENDING FLANGE ENGAGEABLE WITH SAID SHOULDER TO CLOSE SAID OTHER END OF THE INLET CHAMBER, SAID VALVE MEMBER HAVING A LONGITUDINALLY EXTENDING CENTRALLY LOCATED PASSAGE THERETHROUGH CONNECTING SAID PUMPING AND OUTLET CHAMBERS, A RELATIVELY THIN FLEXIBLE INLET VALVE ELEMENT HAVING AN INTERMEDIATE PORTION FIXEDLY CARRIED BY THE OTHER END OF SAID VALVE MEMBER, THE REMAINING PORTION OF SAID INLET VALVE ELEMENT SPANNING THE SPACE BETWEEN SAID VALVE MEMBER AND THE WALLS OF SAID INLET CHAMBER AND ADAPTED TO COOPERATE WITH SAID VALVE SEAT TO CONTROL THE FLOW OF FLUID BETWEEN SAID INLET AND PUMPING CHAMBERS, A RELATIVELY THIN OUTLET VALVE ELEMENT IN SAID OUTLET CHAMBER ADJACENT SAID FLANGE, SAID OUTLET VALVE ELEMENT INCLUDING AN INTEGRAL FLAP VALVE WHICH IS SURROUNDED BY AN ARCUATE PASSAGE HAVING AN ANGULAR EXTENT OF GREATER THAN 180*, SAID FLAP VALVE BEING ADAPTED TO CONTROL FLOW ACROSS SAID PASSAGE BETWEEN SAID PUMPING AND OUTLET CHAMBERS, AN ANNULAR RETAINING ABUTMENT IN SAID OUTLET CHAMBER INCLUDING AN ANNULAR PERIPHERAL FLANGE ENGAGEABLE WITH THE OUTER PERIPHERY OF SAID OUTLET VALVE ELEMENT TO CLAMP SAID OUTLET VALVE ELEMENT AGAINST SAID FLANGE AND SAID FLANGE AGAINST SAID SHOULDER, SAID RETAINING ABUTMENT INCLUDING PASSAGE MEANS THEREIN TO PERMIT FLOW THROUGH SAID OUTLET CHAMBER, AND ACTUATING MEANS FOR MOVING SAID DIAPHRAGM IN A PRESSURE STROKE TO CREATE A PRESSURE WITHIN SAID PUMPING CHAMBER TO URGE SAID FIRST VALVE ELEMENT AGAINST SAID VALVE SEAT TO SEAL SAID INLET CHAMBER FROM SAID PUMPING CHAMBER AND TRANSMIT FLUID FROM SAID PUMPING CHAMBER THROUGH THE PASSAGE IN SAID VALVE MEMBER INTO SAID OUTLET CHAMBER AFTER URGING SAID FLAP VALVE AWAY FROM SAID ONE END OF SAID VALVE MEMBER, SAID ACTUATING MEANS BEING EFFECTIVE TO URGE SAID DIAPHRAGM IN A SUCTION STROKE TO CAUSE SAID FLAP VALVE TO BE URGED IN TIGHT SEALING ENGAGEMENT WITH THE FLANGE OF SAID VALVE MEMBER DUE TO THE PRESSURE OF FLUID IN SAID OUTLET CHAMBER AND TO CAUSE SAID FIRST VALVE ELEMENT TO BE MOVED AWAY FROM SAID VALVE SEAT TO CONNECT SAID INLET CHAMBER WITH SAID PUMPING CHAMBER. 